1. Field of the Invention
The present invention relates generally to devices for management of thermal energy, and more particularly, but not by way of limitation, to a headlight having a heat sink assembly that ensure desirable fluid flow characteristics.
2. Brief Description of Related Art
Numerous systems and methods are known in the art for managing excess thermal energy or heat produced by electrical devices such as light bulbs, LED's, processors, printed circuit boards (PCB's), and the like. Such systems often involve the use of fans and/or heat sinks, such as pin and blade heat sinks. In some systems, one or more fans are used in conjunction with one or more heat sinks to encourage convective heat transfer, in addition to conductive heat transfer, from the heat sink to a cooling fluid such as air, water, or the like. Such heat sink systems may be useful in a number of devices and/or applications.
For example, one application in which such heat sink systems are useful and/or desirable is within, and/or in conjunction with, medical illumination devices. As used herein, medical illumination devices may include surgical, dental, and/or examination illumination devices, and should be understood to be merely one example of illumination devices to which the principles of the invention described herein may be applied. Such illumination devices are often equipped with light sources, such as incandescent bulbs, Xenon bulbs, LED's, coherent light sources, lasers, and the like. Such illumination devices may further be equipped with control equipment such as processors, printed circuit boards (PCB's), and the like. The light sources and/or control equipment may generate thermal energy in quantities in excess of that which can be naturally dissipated to surrounding air. Without a heat sink or other thermal management system and/or device, such excess thermal energy may cause the temperature of the light sources and/or control systems to rise to undesirable levels.
An undesirable rise in temperature, or a rise in temperature to an undesirable level, may result in adverse effects on the light sources and/or control systems. For example, temperatures above a desirable threshold may melt and/or weaken certain materials, may result in undesirable expansion, may increase fatigue on components, may reduce the functional lives of components, may result in undesirable fluctuations in output levels, may change the wavelength, color, and/or other characteristics of light output by light sources, and/or may result in a number of other undesirable effects. As such, it is often desirable to equip medical illumination devices with one or more heat sinks, fans, and/or other thermal management devices and/or equipment to encourage and/or control the dissipation of excess thermal energy so as to maintain desirable and/or tolerable temperatures and thereby encourage stable and desirable operation of an illumination device and components thereof.
However, the addition of one or more heat sinks and/or one or more fans to an illumination device may cause other undesirable effects that must be balanced with the need to dissipate and/or manage excess thermal energy. For example, in certain medical, dental, and/or similar procedures, it may be desirable, and in some circumstances critical, to maintain a sterile work environment. Certain prior illumination devices may be poorly suited for use in the vicinity of such sterile environments, for example, because fans and the like may propel particulates and contaminates into the sterile work environment.
Numerous other factors may be important to consider as well. For example, where an illumination device is in the form of a headlight or headlamp that is worn on the head of a user, such as a doctor, surgeon, dentist, nurse, or the like, the weight, size, balance, and various other physical characteristics are preferably considered and/or optimized. For example, if a headlight becomes excessively heavy, a user may have difficulty wearing the headlight for a sufficient period of time, such as a period of time sufficient to perform an operation or inspection. By way of another example, where a headlight is excessively weighted in one portion relative to another portion, so as to prevent the headlight from balancing comfortably on a user's head, a user may have similar difficulty wearing the headlight for a sufficient period of time. By way of yet another example, a fan that produces excessive noise, vibration, and/or the like may be uncomfortable for a user to wear for a sufficient period of time.